Title: THE METHODOLOGY OF DETERMINING THE GRAIN SIZEBY ACOUSTIC STRUCTURAL NOISE OF STEEL
Abstract: A new approach to the evaluation of the metal structure based on the value of the integral structural level of acousticnoise was found in the development of ultrasonic structuroscopy. There was made the definition of acoustic structural noise of metal. Methods of assessing structural acoustic noise were justified from the position of selection of the frequency range, the control zone, a reference signal and the signal processing algorithm. The experimental results of the use of structural noise to determine the size of the grains were shown on the example of steel 45. Revealed unambiguous relationship between grain size in the samples of investigated steel 45 obtained after the various types of heat treatment and the average amplitude of the structural noise. The obtained dependence is in satisfactory agreement with the theoretical concepts.